West Nile Virus News

TUESDAY, Dec. 6, 2016 – New research hints at why the number of mosquitoes has jumped 10-fold in the past 50 years in certain U.S. states: Increased urbanization and shrinking levels of the pesticide DDT in the environment could be major factors. "At first glance, recent increases in mosquito populations appear to be linked to rising temperatures from climate change, but careful analyses of data over the past century show that it's actually recovery from the effects of DDT," said study co-author Marm Kilpatrick. He is an associate professor of ecology and evolutionary biology at the University of California, Santa Cruz. Still, Kilpatrick said, climate change may be a factor going forward. "On the cold edge of a species' distribution, temperature matters a lot. In Washington, D.C., for example, where Aedes aegypti is not common now, it might become more common if the winters get ... Read more

TUESDAY, Nov. 22, 2016 – The war against infectious diseases – medicine versus microbes – has been holding steady, with the U.S. death rate from these diseases about the same now as it was in 1980, new research says. But some of the specific disease threats have changed over the years, the study authors noted. Researchers found that the national death rate from infections stood at almost 46 deaths per 100,000 people in 2014. That compared with 42 per 100,000 in 1980. There were some major shifts during that time, however. The overall death rate went as high as 63 per 100,000 in 1995, owing to the HIV/AIDS epidemic, according to the study. AIDS deaths declined from then on, with the introduction of the "drug cocktails" that have turned HIV into a manageable chronic disease. But while there was progress against HIV, deaths from pneumonia and flu complications held steady over the ... Read more

MONDAY, Nov. 14, 2016 – A new study suggests that the death toll from the mosquito-borne West Nile virus might be much greater than thought because its effects may often kill people months or years after infection. "We are hoping our research findings will help encourage a push to develop a vaccine that can help prevent disease and premature death," said study co-author Dr. Kristy Murray, an associate professor with National School of Tropical Medicine at Baylor College of Medicine in Houston. "At this time, the only way people can prevent the disease is protecting themselves from mosquito bites, which can sometimes be difficult to do." According to the U.S. Centers for Disease Control and Prevention, almost 44,000 people have been diagnosed with West Nile virus disease since 1999, and many more cases weren't picked up by surveillance. While most infected people don't get sick, an ... Read more

MONDAY, Aug. 8, 2016 – Cardinals, common backyard birds in parts of the United States, may help protect people against West Nile virus, a new study indicates. Researchers wanted to learn why the infection rate for the mosquito-borne virus in Georgia has remained low even though about one-third of birds in the Atlanta area have been exposed to the virus. A similar pattern is evident throughout the Southeast, but the situation is the opposite in many cities in the Northeast and Midwest. For example, West Nile infection rates in Chicago are six times higher than Atlanta's, even though less than 20 percent of birds in Chicago have evidence of infection, the study team said. The researchers focused on birds, particularly American robins. They are considered "super-spreaders" of West Nile because they efficiently pass the virus along to mosquitoes that bite them. Those mosquitoes can then ... Read more

THURSDAY, Jan. 28, 2016 – Efforts to create a Zika vaccine are getting a leg up from lessons learned during earlier battles against other mosquito-borne viruses, U.S. health officials reported Thursday. Researchers are working on two potential vaccines, each based on earlier vaccines created in response to prior outbreaks of West Nile virus and dengue, Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said during a morning news conference. "It is to our advantage that we already have existing vaccine platforms to use as a sort of jumping-off point," Fauci said. A Zika vaccine could be ready for clinical trial by later this year, but Fauci warned that it will likely take years before the vaccine is ready for market. "It is important to understand that we will not have a widely available safe and effective Zika vaccine this year, and probably ... Read more

THURSDAY, Sept. 3, 2015 – West Nile virus, which first appeared in the United States in 1999, continues to be the most common mosquito-borne illness in the country, federal health officials reported Thursday. Of 2,327 cases of mosquito-transmitted disease identified in 2014, there were 2,205 cases of West Nile, according to the U.S. Centers for Disease Control and Prevention. California, Texas and Arizona reported two-thirds of the cases of West Nile, the CDC researchers said. Most people – an estimated 75 percent – infected with West Nile virus won't develop any symptoms, according to the CDC. Less than 1 percent of people will develop a serious neurologic illness, such as encephalitis or meningitis, which is inflammation of the brain or surrounding tissues. Symptoms of severe cases can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or ... Read more

THURSDAY, June 11, 2015 – Diseases spread by mosquitos pose a growing threat to the health of Americans, with the risk at its greatest during these hot summer months. But you wouldn't know that from the amount of money being spent to track West Nile virus, dengue, chikungunya and other illnesses spread by pests like mosquitos, ticks and fleas, a new study reports. Funding has dropped by nearly two-thirds for state and local surveillance programs aimed at preventing insect-borne diseases, according to a report published online June 10 in the journal Emerging Infectious Diseases. The decrease in funding has led to the partial dismantling of these programs, making it tougher to prevent or respond to outbreaks, said study author Dr. James Hadler, a professor of epidemiology at the Yale School of Public Health, in New Haven, Conn. "We can't put out specific information about current or ... Read more

-- Mosquito bites can be more than just an itchy annoyance; they can transmit diseases such as West Nile Virus. The California Department of Public Health suggests how to help prevent mosquito bites: As standing water is a breeding ground for mosquitoes, promptly eliminate any standing water around your home. Stay indoors during the times when mosquitoes are most active, notably at dusk and dawn. Use an insect repellent that protects against mosquitoes, such as those that include DEET, IR-3535, oil of lemon, eucalyptus or picaridin. Check window screens to make sure they do not need repair. Read more

MONDAY, Feb. 10, 2014 – West Nile virus-related hospitalizations and follow-up in the United States cost $778 million in health care expenses and lost productivity from 1999 through 2012, which is much higher than previously reported, according to a new study. That works out to a cost of about $56 million a year over the 14 years examined by the U.S. Centers for Disease Control and Prevention researchers. West Nile virus is transmitted by mosquitoes. About one in five people infected with the virus will develop symptoms such as fever, joint pain and headache. However, about one in 150 will develop a serious nervous system (neurologic) condition such as encephalitis or meningitis and require hospitalization, according to an American Society of Tropical Medicine and Hygiene news release. The researchers examined more than 37,000 cases of West Nile virus reported to the CDC from 1999 ... Read more

TUESDAY, July 16 – An unusually mild winter and an early appearance of infected mosquitoes may have fueled a deadly outbreak of West Nile virus in Texas last summer, a new study finds. Mosquitoes transmit West Nile virus to humans, and while most infections cause no serious problems, a small number of people suffer potentially fatal inflammation around the brain or spinal cord. After several years of laying low, the West Nile virus resurged last summer in the United States, killing 286 people – the most in one year since 1999. Texas accounted for one-third of all confirmed infections, with the Dallas area, where 19 people died, the hardest hit. In the new study, published July 17 in the Journal of the American Medical Association, researchers tried to figure out why. Using local weather data for the past decade, they found that the winters before the 2012 outbreak, and before a ... Read more

MONDAY, May 13 – Higher-than-normal temperatures last year may have led to an increase in West Nile virus cases, say U.S. health officials. More deaths from West Nile virus were reported in 2012 – 286 in all – than in any year since 1999, when the mosquito-borne disease was first detected in the United States, the U.S. Centers for Disease Control and Prevention reported Monday. And the total number of cases – 5,674 – was the largest on record since 2003. "Last summer's outbreak likely resulted from many factors, including higher-than-normal temperatures that influenced mosquito and bird abundance, the replication of the virus in its host mosquitoes, and interactions of birds and mosquitoes in hard-hit areas," the CDC stated in an advisory. Texas accounted for 33 percent of all reported West Nile virus cases in 2012, the agency said. Other states with the greatest concentration of ... Read more

WEDNESDAY, Oct. 17 – The number of West Nile virus cases this year has surpassed 4,500, U.S. health officials reported Wednesday, and the number of deaths has reached 183, up from 168 last week. As of Tuesday, 48 states had reported West Nile infections in people, birds or mosquitoes. A total of 4,531 cases involved people. Of these cases, 51 percent were classified as neuroinvasive disease (such as meningitis or encephalitis) and 49 percent were classified as non-neuroinvasive disease. The 4,531 cases are the highest number reported through the third week of October since 2003. Almost 70 percent of the reported cases are from eight states – Texas, California, Louisiana, Mississippi, Illinois, South Dakota, Michigan and Oklahoma – and more than one-third have been reported in Texas, according to the U.S. Centers for Disease Control and Prevention. The best way to avoid the virus is ... Read more

WEDNESDAY, Oct. 10 – The number of new West Nile virus cases continued to rise in the past week, and the death toll now stands at 168, up from 163 last week, U.S. health officials reported Wednesday. As of Tuesday, 48 states had reported West Nile infections in people, birds or mosquitoes. A total of 4,249 cases involved people. Of these cases, 2,123 (50 percent) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 2,126 (50 percent) were classified as non-neuroinvasive disease. The total number of West Nile cases reported so far in 2012 is the highest since 2003. Seventy percent of the cases have been reported from eight states – Texas, South Dakota, Oklahoma, Mississippi, Michigan, Louisiana, Illinois and California – and over a third of all cases have been in Texas, according to the U.S. Centers for Disease Control and Prevention. The best way to avoid ... Read more

WEDNESDAY, Oct. 3 – The number of new West Nile virus cases continued to rise in the past week, and the death toll now stands at 163, up from 147 last week, U.S. health officials reported Wednesday. As of Tuesday, 48 states had reported West Nile infections in people, birds, or mosquitoes. A total of 3,969 cases involved people. Of these cases, 2,010 (51 percent) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 1,959 (49 percent) were classified as non-neuroinvasive disease. The total number of West Nile cases reported so far in 2012 is the highest since 2003. Seventy percent of the cases have been reported from eight states – Texas, South Dakota, Oklahoma, Mississippi, Michigan, Louisiana, Illinois and California – and one-third of all cases have been in Texas, according to the U.S. Centers for Disease Control and Prevention. The best way to avoid ... Read more

WEDNESDAY, Sept. 26 – The number of new West Nile virus cases jumped by more than 400 since last week, and the death toll now stands at 147, up from 134, U.S. health officials reported Wednesday. As of Tuesday, 48 states had reported West Nile infections in people, birds, or mosquitoes. A total of 3,545 cases involved people. Of these cases, 1,816 (51 percent) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 1,729 cases (49 percent) were classified as non-neuroinvasive disease. The total number of West Nile cases reported so far in 2012 is the highest since 2003. Seventy percent of the cases have been reported from eight states – Texas, South Dakota, Oklahoma, Mississippi, Michigan, Louisiana, Illinois and California – and 38 percent of all cases have been in Texas, according to the U.S. Centers for Disease Control and Prevention. This makes it one of ... Read more